Dodge ESX3 Powertrain Keeps the Fun in Driving a Fuel-Efficient Vehicle

23 February 2000
Dodge ESX3 Powertrain Keeps the Fun in Driving a Fuel-Efficient Vehicle
    WASHINGTON, Feb. 22 -- In two years, DaimlerChrysler
engineers have increased fuel efficiency to 72 miles per gallon (3.3
liters/100 km), improved acceleration and enhanced driveability -- while
cutting the cost penalty in half.
    "A two-mile-per-gallon improvement might not sound like a huge engineering
accomplishment, but this car also accelerates faster and provides a smoother,
quieter ride while being less aerodynamic than its predecessor, the Dodge
Intrepid ESX2," explained Tom Moore, Vice President - DaimlerChrysler Liberty
& Technical Affairs.  "We also cut the cost penalty in half -- from $15,000
down to $7,500 -- in two years."
    Much of the driving pleasure is the result of ESX3's unique EMAT
transmission that combines two separate clutches in a computer-controlled,
six-speed system that provides the shifting smoothness of an automatic
transmission with the fuel efficiency of a manual.  The EMAT transmission uses
two clutches acting in tandem to provide seamless acceleration, with no torque
interrupt during shifts.  The typical manual transmission is 10 percent more
fuel efficient than an automatic transmission.
    "The EMAT is a vital link in helping us achieve up to 80 miles per gallon
(2.9 liters/100 km)," said Tom Kizer, Director of Advanced Powertrain and
Electrical Engineering at DaimlerChrysler Liberty.  "All this technology is
invisible to the driver, who sees the typical automatic transmission
selections of Park, Reverse, Neutral and Drive."
    The mybrid powertrain, consisting of a three-cylinder, 1.5 liter,
all-aluminum direct-injected diesel engine and 15 kilowatt peak power electric
motor, advances development of the powertrain in the ESX2.
    As in the ESX2, the Dodge ESX3 mybrid powertrain reduces fuel energy use
by
only relying on the electric motor and battery to capture braking energy and
reuse it to power accessories and provide a boost during hard acceleration.
For additional fuel savings, the engine automatically shuts off when the
vehicle is stopped, and the electric motor instantly restarts the engine when
the accelerator pedal is pressed.
    At 106 pounds (48 kg), the SAFT lithium-ion battery pack weighs less and
is
more compact than other battery options while providing more energy.  The
battery pack is fully integrated with cooling and control systems and is small
enough to be installed between the rear seat and trunk, between the rear wheel
housings.  This provides ample cargo space of 16 cubic feet (450 liters) in
the trunk.
    Weight savings continue through the rest of the ESX3 powertrain -- the
engine weighs less than 250 pounds (113 kg), the air-cooled motor just 76
pounds (33 kg).  In fact, the mybrid powertrain weighs less than a
conventional powertrain that relies on only one combustion engine.
    In addition to the significant challenge of developing highly fuel
efficient
cars, PNGV engineers are also working on solutions to further reduce exhaust
emissions.  While the Dodge ESX3 meets the initial emission targets set by the
Partnership in 1993, continued work on low-sulfur and synthetic fuels, new
exhaust aftertreatment technologies and cleaner combustion processes are
necessary to meet future standards.